The promise of a closer union between organizational and historical research has long been recognized. However its potential remains unfulfilled: the authenticity of theory development expected by organization studies and the authenticity of historical veracity required by historical research place exceptional conceptual and empirical demands on researchers. We elaborate the idea of historical organization studies, organizational research that draws extensively on historical data, methods and knowledge to promote historically informed theoretical narratives attentive to both disciplines. Building on prior research, we propose a typology of four differing conceptions of history in organizational research: history as evaluating, explicating, conceptualizing, and narrating. We identify five principles of historical organization studies - dual integrity, pluralistic understanding, representational truth, context sensitivity and theoretical fluency - and illustrate our typology holistically from the perspective of institutional entrepreneurship. We explore practical avenues for a creative synthesis, drawing examples from social movement research and micro-history. Historically informed theoretical narratives whose validity derives from both historical veracity and conceptual rigor, afford dual integrity that enhances scholarly legitimacy, enriching understanding of historical, contemporary and future-directed social realities.